By plugging in a 500mb portable hard drive into the back, it expands to give me 700 hours of recording time. Bell Satellite (my provider), doesn't publicize this, but we learned this trick from the tech who installed it. He told us to return the $600 dvr receiver for the $200 HD recive and we were able to instantly expand the dvr capabilities.

Yeah, I know, who really needs 700 hours of time? You'd be surprised how quickly we burn through that!